Method and system for nvh control

ABSTRACT

Methods and systems are provided for reducing driver dissatisfaction from NVH associated with cylinder deactivation. Audio and video feed is captured from inside a vehicle and analyzed to infer if a vehicle operator is distracted. If yes, then a VDE transition is scheduled to occur during the time when the driver is distracted and unlikely to notice the NVH.

FIELD

The present description relates generally to methods and systems forcontrolling VDE transitions in a vehicle engine to reduce NVH inducedcustomer dissatisfaction.

BACKGROUND/SUMMARY

Some engines, known as a variable displacement engines (VDE), may beconfigured to operate with a variable number of active and deactivatedcylinders to increase fuel economy. Therein, a portion of the engine'scylinders may be disabled during selected conditions defined byparameters such as a speed/load window, as well as various otheroperating conditions including engine temperature. An engine controlsystem may disable a selected group of cylinders, such as a bank ofcylinders, through the control of a plurality of cylinder valvedeactivators that affect the operation of the cylinder's intake andexhaust valves, through the control of a plurality of selectivelydeactivatable fuel injectors that affect cylinder fueling, and/orthrough the control of the ignition system to selectively control (e.g.,withhold) spark to deactivatable cylinders. By deactivating enginecylinders at low speeds/light loads, associated pumping losses can beminimized, and engine efficiency is increased.

However, noise, vibration, and harshness (NVH) may be caused duringengine transitions between a VDE state where one or more cylinders aredeactivated, and a non-VDE state where all cylinders are active.Specifically, the engine's crankshaft and firing order are defined toreduce NVH when all cylinders are active. Engine torque production andengine speed may be smoothest (e.g., producing least variation fromdesired engine torque and desired engine speed) when the engine isoperated with its full complement of cylinders. In the VDE state, enginetorque variation and engine speed variation from desired values mayincrease because of longer intervals between combustion events. As aresult, NVH from the engine during a VDE state, as observed by vehicleoccupants, may increase. If the engine is operated with higher levels ofnoise and vibration, vehicle occupants may find riding in the vehicleobjectionable. Thus, it may be difficult to provide higher levels offuel efficiency without degrading the driving experience.

One example approach for reducing the VDE associated NVH is shown byRollinger et al. in U.S. Pat. No. 10,006,379. Therein, a larger numberof VDE states are enabled when an estimate of road roughness iselevated. Consequently, an engine can be operated in the VDE mode whenthe NVH associated with the VDE transition can be masked by roadroughness and vehicle occupants are less likely to notice the NVH.

However the inventors herein have identified potential issues with suchan approach. As one example, rough roads may be far and few in between.As a result, relying on road roughness may result in limitedopportunities to enable VDE operation.

The inventors have recognized that there may be other conditions where avehicle driver is distracted that can be leveraged for providing moreopportunities for VDE operation. For example, during conditions when adriver is engaged in in-cabin conversation (or otherwise distracted), orwhen cabin speakers are operating at an elevated volume, the driver maynot notice the NVH. Likewise, the NVH may not be perceived when ambientnoise around the car is elevated.

Further still, if the vehicle operator is a transient driver, such asmay occur due to car sharing, the driver may not be as concerned aboutthe vehicle's NVH as long as the vehicle is performing the main task oftransporting the driver to the desired location. The same may be truefor a vehicle occupant if the vehicle is a driverless autonomousvehicle. During such conditions, cylinder deactivation does not need tobe limited on account of driving experience being affected by NVH.

Thus in one example, NVH related to cylinder deactivation may be betterbalanced with fuel economy by a method comprising: initiating atransition between operating an engine with more cylinders active tooperating with fewer cylinders active in response to one or more ofaudio and video feed captured at the vehicle.

As an example, various vehicle sensors may be used to capture in-vehicleas well as ambient vehicle noise. Likewise, vehicle cameras may be usedto monitor occupant behavior. The audio and video feeds may be analyzed,for example using voice-recognition software to identify if the driveris engaged in conversation, and using image analysis (such as eyemovement, hand movement, etc.) to identify if the driver is exhibitingdistracted behavior. A vehicle controller may schedule a VDE transition(from a non-VDE mode to a VDE mode, or vice versa) to occur while thedriver is talking or distracted, as inferred based on the audio and/orvideo feed captured inside (or outside) the vehicle. Furthermore, VDEmay be controlled based on engine operating conditions, and with reducedconstraints regarding driver dissatisfaction, during conditions when thevehicle is used for car sharing or when the vehicle is drivenautonomously. Consequently, it may be possible to provide the technicalresult of operating an engine cylinder in a cylinder deactivation modeat a time when vehicle occupants are not likely to notice the additionalengine noise and vibration.

The present description may provide several advantages. In particular,the approach may provide improved vehicle fuel economy by enablingcylinder deactivation to be applied over a larger portion of a drivecycle. In addition, the approach may reduce the possibility ofdisturbing occupants of a vehicle while cylinders are deactivated orwhile they are transitioned between active and deactivated states.Further, the approach may enable cylinder deactivation responsive toaudio and video feed captured inside and outside the vehicle so thatfuel economy may be increased while vehicle occupants are lesssusceptible to noise and vibration that may be related to deactivatingengine cylinders.

It should be understood that the summary above is provided to introducein simplified form a selection of concepts that are further described inthe detailed description. It is not meant to identify key or essentialfeatures of the claimed subject matter, the scope of which is defineduniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages described herein will be more fully understood by readingan example of an embodiment, referred to herein as the DetailedDescription, when taken alone or with reference to the drawings, where:

FIG. 1 is a schematic diagram of a vehicle system including a variabledisplacement engine.

FIGS. 2A and 2B are schematic diagrams of example variable displacementengine configurations.

FIGS. 3A and 3B show examples of cylinder deactivation regions.

FIG. 4 shows a flow chart of an example method for controlling an engineto reduce customer dissatisfaction due to NVH associated with cylinderdeactivation.

FIG. 5 shows a flow chart of an example method for capturing andanalyzing vehicle audio and video feed to identify opportunities forcylinder deactivation.

FIG. 6 shows a prophetic example of adjusting a number of operatingengine cylinders based on driver distraction.

FIG. 7 shows a flow chart of an example method for adjusting VDEthresholds based on audio and/or video feed captured at a vehicle.

DETAILED DESCRIPTION

The following description relates to systems and methods for improvingvariable displacement engine (VDE) operation and vehicle drivabilityduring conditions where engine cylinders may be deactivated to improvevehicle fuel efficiency. Cylinders of an engine as shown in FIGS. 1-2Bmay be selectively deactivated to improve engine fuel efficiency. Enginecylinders may be deactivated in an engine operating range defined byengine speed and load as shown in FIGS. 3A and 3B. An engine controllermay execute a control routine, such as the example routine of FIG. 4 toopportunistically initiate a VDE transition during conditions when avehicle driver is distracted and less likely to be inconvenienced by NVHassociated with cylinder deactivation. Driver distraction may beinferred based on an analysis of audio and video feed captured at thevehicle, as shown at FIG. 5. The controller may also adjust engine speedand load thresholds at which a VDE transition is enabled based on thepresence of audio and video feed, as shown at FIG. 7. FIG. 6 shows aprophetic example of adjusting VDE operations of an engine based oninferred driver distraction.

FIG. 1 schematically shows aspects of an example vehicle system 100,including an engine system 101 having an engine 10 coupled in a vehicle102. In the depicted example, vehicle 102 is a hybrid electric vehiclewith multiple sources of torque available to one or more vehicle wheels47. However in alternate examples, vehicle system 100 may include aconventional non-hybrid powertrain. In the example shown, a powertrainof vehicle 102 includes engine 10 and an electric machine 52. Electricmachine 52 may be a motor or a motor/generator. Engine 10 and electricmachine 52 are connected to vehicle wheels 47 via a transmission 48 whenone or more clutches 53 are engaged. In the depicted example, a (first)clutch 53 is provided between engine 10 and electric machine 52, and a(second) clutch 53 is provided between electric machine 52 andtransmission 48. A controller 12 may send a signal to an actuator ofeach clutch 53 to engage or disengage the clutch, thereby connecting ordisconnecting engine 10 from electric machine 52 and the componentsconnected thereto and/or connecting or disconnecting electric machine 52from transmission 48 and the components connected thereto. For example,torque from engine 10 may be transferred to vehicle wheels 47 via acrankshaft 40, transmission 48, and a powertrain shaft 84 when clutches53 are engaged. Transmission 48 may be a gearbox, a planetary gearsystem, or another type of transmission. Transmission 48 may be a fixedratio transmission that includes a plurality of gear ratios to allowengine 10 to rotate at a different speed than wheels 47. By changing atorque transfer capacity of first clutch 53 (e.g., an amount of clutchslippage), an amount of engine torque relayed to the wheels viapowertrain shaft 84 (herein also referred to as the driveline) may bemodulated. In the depicted example, electric machine 52 is an electricmotor coupled in the drivetrain between the engine and the transmission.However, additional electric machines may be coupled to crankshaft 40.

The powertrain may be configured in various manners, including as aparallel, a series, or a series-parallel hybrid vehicle. In electricvehicle embodiments, a system electrical energy device, such as systembattery 45 may be coupled to the driveline. System battery 45 a may be atraction battery, for example a 48V battery that delivers electricalpower to electric machine 52 to provide torque to vehicle wheels 47. Insome embodiments, electric machine 52 may also be operated as agenerator to provide electrical power to charge system battery 45, forexample, during a braking operation using regenerative torque. It willbe appreciated that in other embodiments, including non-electric vehicleembodiments, system battery 45 may be a typical starting, lighting,ignition (SLI) battery coupled to an alternator 46. It will beappreciated that while the system electrical energy storage device 45 isdepicted herein as a battery, in other examples, the electrical energystorage device 45 may be a capacitor.

In the depicted embodiment, engine 10 is a boosted engine configuredwith a boosting device, herein shown as turbocharger 15. Turbocharger 15includes compressor 114 that is mechanically coupled to, and driven by,turbine 116 via a shaft 19, the turbine 116 driven by expanding engineexhaust. In one embodiment, the turbocharger may be a twin scrolldevice. In another embodiment, the turbocharger may be a variablegeometry turbocharger (VGT), wherein turbine geometry is actively variedas a function of engine operating conditions. Fresh air is introducedalong intake passage 42 into engine 10 via air box 112 and flows tocompressor 114. Air is then compressed at compressor 114 and introducedinto engine 10.

Compressor 114 is coupled to a throttle valve 20 through a charge-aircooler (CAC) 18 (also referred to as an intercooler herein). Air flowsfrom compressor 114 through CAC 18 and throttle valve 20 to an intakemanifold 22. CAC 18 may be an air-to-air or water-to-air heat exchanger,for example. Intake manifold pressure (e.g., a pressure of the aircharge within the intake manifold) may be determined using a manifoldabsolute pressure (MAP) sensor 124.

Intake manifold 22 is coupled to a series of combustion chambers 30through a series of intake valves 150. The combustion chambers arefurther coupled to an exhaust manifold 36 via a series of exhaust valves156. In the depicted embodiment, a single exhaust manifold 36 is shown.However, in other embodiments, the exhaust manifold may include aplurality of exhaust manifold sections. Configurations having aplurality of exhaust manifold sections may enable effluent fromdifferent combustion chambers to be directed to different locations inthe engine system.

In one embodiment, each of the exhaust and intake valves may beelectronically actuated or controlled. In another embodiment, each ofthe exhaust and intake valves may be cam actuated or controlled. Whetherelectronically actuated or cam actuated, the timing of exhaust andintake valve opening and closure may be adjusted for the desiredcombustion and emissions-control performance. For example, the camtiming may be adjusted via a variable cam timing system to move theintake and exhaust cams to a position that provides the optimalvolumetric efficiency for the given operating conditions.

Combustion chambers 30 may be supplied one or more fuels, such asgasoline, alcohol fuel blends, diesel, biodiesel, compressed naturalgas, etc. Fuel may be supplied to the combustion chambers via directinjection, port injection, throttle valve-body injection, or anycombination thereof. In the depicted example, fuel is provided to eachcombustion chamber 30 via direct injection by a fuel injector 66 (whileonly one fuel injector is shown in FIG. 1, each combustion chamberincludes a fuel injector coupled thereto). Fuel may be delivered to fuelinjector 66 by a fuel system (not shown) including a fuel tank, a fuelpump, and a fuel rail. In the combustion chambers, combustion may beinitiated via spark ignition and/or compression ignition.

As shown in FIG. 1, exhaust from exhaust manifold 36 is directed toturbine 116 to drive the turbine. When reduced turbine torque isdesired, a portion of exhaust may be directed instead through awaste-gate 90, bypassing the turbine. A waste-gate actuator 92 (e.g.,waste-gate valve) may be actuated open to relieve at least some exhaustpressure from upstream of turbine 116 to a location downstream ofturbine 116 via waste-gate 90. By reducing exhaust pressure upstream ofturbine 116, turbine speed may be reduced.

The combined flow from turbine 116 and waste-gate 90 flows through anemission control device 70. In general, emission control device 70 mayinclude one or more exhaust after-treatment components configured toreduce an amount of one or more substances in the exhaust flow. Forexample, one exhaust after-treatment component may be configured to trapNO_(x) from the exhaust flow when the exhaust flow is lean and to reducethe trapped NO_(x) when the exhaust flow is rich. In other examples, anexhaust after-treatment component may be configured to disproportionateNO_(x) or to selectively reduce NO_(x) with the aid of a reducing agent.In still other examples, emission control device 70 includes a three-waycatalyst configured to oxidize residual hydrocarbons and carbon monoxidewhile reducing NO_(x) in the exhaust flow. Different exhaustafter-treatment catalysts having any such functionality may be arrangedin wash coats or elsewhere in emission control device 70, eitherseparately or together. In some embodiments, the emission control device70 may further include a regeneratable soot filter configured to trapand oxidize soot particles in the exhaust flow.

All or part of the treated exhaust from emission control device 70 maybe released into the atmosphere via an exhaust conduit 35. Depending onoperating conditions, however, some exhaust may be diverted instead tointake passage 42 via an exhaust gas recirculation (EGR) passage (notshown), including an EGR cooler and an EGR valve. EGR may berecirculated to the inlet of compressor 114.

One or more sensors may be coupled to the inlet of compressor 114. Forexample, a temperature sensor 55 may be coupled to the inlet ofcompressor 114 for estimating a compressor inlet temperature. As anotherexample, a pressure sensor 56 may be coupled to the inlet of compressor114 for estimating a pressure of air entering the compressor. Stillother sensors may include, for example, air-fuel ratio sensors, humiditysensors, etc. In other examples, one or more of the compressor inletconditions (such as humidity, temperature, pressure, etc.) may beinferred based on engine operating conditions. In addition, a throttleinlet pressure (TIP) sensor 59 may be coupled downstream of CAC 18 andupstream of throttle valve 20 for estimating a boost pressure deliveredto the engine.

Engine 10 may be a variable displacement engine (VDE), having one ormore cylinders 30 with selectively deactivatable intake valves 150 andselectively deactivatable exhaust valves 156. Therein, selectedcylinders may be deactivated by shutting off the respective cylindervalves, as elaborated below. In one example, intake valves 150 andexhaust valves 156 are configured for electric valve actuation (EVA) viaelectric individual cylinder valve actuators. While the depicted exampleshows each cylinder having a single intake valve and a single exhaustvalve, in alternate examples, each cylinder may have a plurality ofselectively deactivatable intake valves and/or a plurality ofselectively deactivatable exhaust valves.

In some examples, engine 10 may have additionally have selectivelydeactivatable (direct) fuel injectors 66 and the selected cylinders maybe deactivated by shutting off the respective fuel injectors whilemaintaining operation of the intake and exhaust valves such that air maycontinue to be pumped through the cylinders.

During the deactivation, selected cylinders may be deactivated byclosing individual cylinder valve mechanisms (e.g., VDE mechanisms),such as intake valve mechanisms, exhaust valve mechanisms, or acombination of both. Cylinder valves may be selectively deactivated viahydraulically actuated lifters (e.g., lifters coupled to valvepushrods), via a cam profile switching mechanism in which a cam lobewith no lift is used for deactivated valves, or via the electricallyactuated cylinder valve mechanisms coupled to each cylinder. Inaddition, fuel flow to the deactivated cylinders may be stopped, such asby deactivating cylinder fuel injectors 66. In some examples, spark tothe deactivated cylinders may also be stopped, such as by selectivelycontrolling the vehicle ignition system to only deliver spark to activecylinders.

As elaborated at FIGS. 2A-2B, during selected conditions, such as whenthe full torque capability of the engine is not needed, one or morecylinders of engine 10 may be selected for selective deactivation(herein also referred to as individual cylinder deactivation). Enginecontroller 12 may continually analyze individual cylinders, determiningwhether to activate or deactivate each cylinder based on a driver'spedal position input and torque demands. As such, engine NVH may beelevated when at least some cylinders are deactivated due to enginetorque variation and engine speed variation from desired values becauseof longer intervals between combustion events. This NVH may beobjectionable to a vehicle driver, limiting the opportunities for VDEoperation. As elaborated at FIG. 4, various vehicle sensors and devicesmay be used to capture audio and video feed from inside the vehicle toidentify periods when the vehicle driver may be distracted, andtherefore less likely to be offended by the NVH associated with cylinderdeactivation. By opportunistically enabling VDE during those periods, ifengine speed and load conditions are conducive for cylinderdeactivation, additional VDE related fuel economy benefits can beachieved without dissatisfying the driver. Further, as elaborated atFIG. 7, the audio and video feed may be use to adjust engine speed andload thresholds at which VDE is enabled and disabled.

Various sensors and devices may be coupled to vehicle 102 for capturingaudio and feed from within the vehicle, as well for capturing audio andvideo feed regarding an environment of the vehicle. Based on the audioand video feed, it may be determined by controller 12 if the driver islikely to notice any VDE related NVH. As elaborated at FIGS. 4-5, and 7,the captured audio and video feed may be analyzed to infer in a vehicledriver is distracted.

For example, the vehicle may include an audio system 170 for capturingaudio feed from inside and outside the vehicle. Audio feed may becaptured at audio system 170 at predefined intervals. The audio system170 may include an entertainment system 172 for streaming audio inputinto the vehicle cabin, such as from a radio, a CD, or other musicsource. The entertainment system 172 may include in-cabin speakers 174for streaming music from the music source into the vehicle cabin. If thevolume setting of in-cabin speakers 174, as selected by the vehicledriver, is higher than a non-zero threshold, it may be inferred by thecontroller 12 that the driver is not likely to notice any NVH emanatingfrom VDE controls.

As another example, audio system 170 may include audio sensors 176 forcapturing sounds from the vehicle cabin. The captured sounds may includeengine noise, motor noise, conversations between vehicle occupants, etc.The controller 12 may include software for analysis the sounds, such asvoice-recognition software for identifying the vehicle driver's voice.Still other audio analysis and voice recognition techniques may be usedto discern the voice of the driver from the different sounds captured inthe vehicle cabin. If, based on the on-board voice recognitiontechniques, it is determined that the driver is engaged in an in-cabinconversation, then the controller 12 may infer that the driver is notlikely to notice NVH emanating from VDE controls.

As yet another example, audio system 170 may include a connected device179, such as a smartphone or music player. The connected device 179 maybe communicatively coupled to the speakers 174 of the entertainmentsystem 172, and an in-cabin microphone 178, such as via Bluetooth, Sync,or other software allowing for hands free control of the device. Inparticular, the connected device 179 may be operated via voice commandsreceived from the vehicle driver at the microphone 178. In one example,the microphone 178 is positioned in the sun visor of the vehicle. Duringconditions when a vehicle occupant is speaking on the connected device179, or providing voice commands on the microphone, they may bedistracted and unlikely to observe NVH. Additionally, the microphone 178may be repurposed to capture audio feed from the cabin which is thenanalyzed by voice-recognition techniques at the controller to determineif the driver is engaged in an in-cabin conversation. If so, thecontroller 12 may infer that the driver is not likely to notice NVHemanating from VDE controls.

Audio sensors 176 may also be used to capture audio feed from outsidethe vehicle cabin, such as in the vehicle's environment. For example, afirst set of audio sensors may be coupled to an interior of the vehiclefor capturing in-cabin audio feed while a second set of audio sensorsmay be coupled to an exterior of the vehicle for capturing ambient audiofeed. Ambient sounds captured may include city noise, traffic noise,construction noise, etc., in the environment of the vehicle. If theambient noise around the vehicle is elevated, it may be inferred thatthe noise may mask any VDE noise.

Likewise, the vehicle may include a video system 180 for capturing videofeed from inside the vehicle cabin. The video system 180 may include acamera 182. In one example, a dashboard camera coupled to a dashboard ofthe vehicle cabin may be repurposed for capturing images of activityinside the cabin. As another example, a dedicated camera may be providedwith a focal point focused on the driver for monitoring driver behavior.The video system 180 may additionally or optionally include a device forproviding machine vision 184. The machine vision may capture video feedof an interior of the vehicle cabin. Likewise, the video system 180 mayinclude in-cabin video sensors 184. The captured video feed may includestill images, time lapsed images, and/or videos. Images may be capturedat predefined intervals. The captured video feed be analyzed by imageanalysis software to identify behavior patterns of the vehicle driver.If the behavior patterns are indicative of distracted behavior, such asrapid eye movement, frequent hand movement, identification of specificgestures, etc. then it may be inferred that the driver is unlikely tonotice the VDE associated NVH. Still other patterns indicative of adistracted driver include frequent or constant side to side headmovement, eye movement indicating focus on outside scenery, handmovement/interaction with vehicle cabin controls (HMI), busy steering(e.g., vehicle drifting), frequent lane changes (e.g., in hurry to getto destination), erratic harsh braking, and vehicle speed thatconsistently mismatches the advertised or recommended road speed.

As elaborated at FIG. 7, the controller may infer that the driver isdistracted with a confidence factor based on the captured and analyzedaudio and video feed. As an example, driver distraction inferred basedon only audio feed or only video feed may be assigned a lower confidencefactor. In comparison, if both the audio feed and video feed isindicative of driver distracted behavior, then a higher confidencefactor may be assigned. In response to the lower confidence factor, VDEthresholds (that is engine speeds and loads at which VDE is allowed tobe initiated) may be extended by a first amount while responsive to thehigher confidence factor, VDE thresholds may be extended by a secondamount, larger than the first amount. For example, if cylinderdeactivation is enabled when engine speed and engine load are in a firstrange, extending VDE thresholds by the first amount may include enablingcylinder deactivation when engine speed and engine load are in a secondrange including a higher engine speed and a higher engine load that thefirst range. Likewise, extending VDE thresholds by the second amount mayinclude enabling cylinder deactivation when engine speed and engine loadare in a third range including a higher engine speed and a higher engineload that the second range. As another example, if the default VDEthreshold includes deactivating a first number of cylinders when enginespeed and load are in a defined range, extending VDE thresholds by thefirst amount may include enabling a second number of cylinders, largerthan the first number, to be deactivated when engine speed and engineload are in the given range, and extending VDE thresholds by the secondamount may include deactivating a third number of cylinders, larger thanthe second number, to be deactivated when engine speed and engine loadare in the given range.

Controller 12 may be included in a control system 14. Controller 12 isshown receiving information from a plurality of sensors 16 (variousexamples of which are described herein) and sending control signals to aplurality of actuators 81 (various examples of which are describedherein). As one example, sensors 16 may include an exhaust gas sensor126 located upstream of turbine 116, MAP sensor 124, an exhausttemperature sensor 128, an exhaust pressure sensor 129, compressor inlettemperature sensor 55, compressor inlet pressure sensor 56, a mass airflow (MAF) sensor 57, barometric pressure sensor 58, and TIP sensor 59.Other sensors, such as additional pressure, temperature, air/fuel ratio,and composition sensors, may be coupled to various locations in vehiclesystem 100. In addition or in place of the depicted sensors, thecontroller may infer or model values for pressures, temperatures and/orflow rates based on operating conditions. Input may also be receivedfrom still other vehicle sensors and devices, such as the varioussensors, devices, and components of audio system 170 and video system180.

The actuators 81 may include, for example, throttle valve 20, CCRV 62,electric motor 108, waste-gate actuator 92, BISG 114, and fuel injector66. Still other actuators include microphone 178, in-cabin speakers 174,camera 182, etc. Controller 12 may receive input data from the varioussensors, process the input data, and employ the various actuators toadjust vehicle and engine operation based on the received signals andinstructions stored on a memory of the controller. The controller mayemploy the actuators in response to the processed input data based oninstruction or code programmed therein corresponding to one or moreroutines, such as example control routines described herein with regardto FIG. 4. As an example, responsive to an indication from audio sensorsthat the sound level inside the vehicle cabin is higher than athreshold, or responsive to an indication from the audio and videosensors that the driver is engaged in in-cabin conversation, thecontroller may initiate a VDE transition. This may include deactivatinga larger number of cylinders at a given engine speed-load conditionresponsive to elevated cabin noise or driver distraction.

During operation, each cylinder 30 within engine 10 typically undergoesa four stroke cycle: the cycle includes the intake stroke, compressionstroke, expansion stroke, and exhaust stroke. During the intake stroke,generally, the exhaust valve 156 closes and intake valve 150 opens. Airis introduced into combustion chamber 30 via intake manifold 22, and apiston (not shown) moves to the bottom of the cylinder so as to increasethe volume within combustion chamber 30. The position at which thepiston is near the bottom of the cylinder and at the end of its stroke(e.g., when combustion chamber 30 is at its largest volume) is typicallyreferred to by those of skill in the art as bottom dead center (BDC).During the compression stroke, intake valve 150 and exhaust valve 156are closed. Piston moves toward the cylinder head so as to compress theair within combustion chamber 30. The point at which piston 36 is at theend of its stroke and closest to the cylinder head (e.g., whencombustion chamber 30 is at its smallest volume) is typically referredto by those of skill in the art as top dead center (TDC). In a processhereinafter referred to as injection, fuel is introduced into thecombustion chamber. In a process hereinafter referred to as ignition,the injected fuel is ignited by known ignition means such as spark plug,resulting in combustion. During the expansion stroke, the expandinggases push piston back to BDC. Crankshaft 40 converts piston movementinto a rotational torque of the rotary shaft. Finally, during theexhaust stroke, the exhaust valve 156 opens to release the combustedair-fuel mixture to exhaust manifold 36 and the piston returns to TDC.Note that the above is shown merely as an example, and that intake andexhaust valve opening and/or closing timings may vary, such as toprovide positive or negative valve overlap, late intake valve closing,or various other examples.

Referring now to FIG. 2A, a first configuration of engine 10 is shown.Engine 10 includes two cylinder banks 202 and 204. First cylinder bank204 includes cylinders 210 numbered 1-4. Second cylinder bank 202includes cylinders 210 numbered 5-8. Thus, the first configuration is aV8 engine comprising two cylinder banks. All cylinders operating may bea first cylinder operating mode.

During select conditions, one or more of cylinders 210 may bedeactivated via ceasing to flow fuel to the deactivated cylinders.Further, air flow to deactivated cylinders may cease via closing andholding closed intake and exhaust valves of the deactivated cylinders.The engine cylinders may be deactivated in a variety of patterns toprovide a desired actual total number of activated or deactivatedcylinders. For example, cylinders 2, 3, 5, and 8 may be deactivatedforming a first pattern of deactivated cylinders and a second cylinderoperating mode. Alternatively, cylinders 1, 4, 6, and 7 may bedeactivated forming a second pattern of deactivated cylinders and athird cylinder operating mode. In still another example, cylinders 2 and8 may be deactivated forming a third pattern of deactivated cylindersand a fourth cylinder operating mode. In yet another example, cylinders3 and 5 may be deactivated forming a fourth pattern of deactivatedcylinders and a fifth cylinder operating mode. In this example, fivecylinder operating modes are provided; however, additional or fewercylinder operating modes may be provided. If engine conditions are suchthat the engine may operate in any of the five cylinder modes described,the engine may be described as having five available cylinder operatingmodes. In this example, if two of the engine's five operating modes arenot available, the engine may be described as having three availableoperating modes. The engine always has one available cylinder operatingmode (e.g., all cylinders active and combusting air and fuel). Ofcourse, the actual total number of available operating modes may be morethan or less than five depending on the engine configuration.

Referring now to FIG. 2B, a second configuration of engine 10 is shown.Engine 10 includes one cylinder bank 206. Cylinder bank 206 includescylinders 210 numbered 1-4. Thus, the first configuration is an I4engine comprising one cylinder bank. All cylinders operating may be afirst cylinder operating mode for this engine configuration.

Similar to the first configuration, one or more of cylinders 210 may bedeactivated via ceasing to flow fuel to the deactivated cylinders.Further, air flow to deactivated cylinders may cease via closing andholding closed intake and exhaust valves of the deactivated cylinders.The engine cylinders may be deactivated in a variety of patterns toprovide a desired actual total number of activated or deactivatedcylinders. For example, cylinders 2 and 3 may be deactivated forming afirst pattern of deactivated cylinders and a second cylinder operatingmode. Alternatively, cylinders 1 and 4 may be deactivated forming asecond pattern of deactivated cylinders and a third cylinder operatingmode. In still another example, cylinder 2 may be deactivated forming athird pattern of deactivated cylinders and a fourth cylinder operatingmode. In yet another example, cylinder 3 may be deactivated forming afourth pattern of deactivated cylinders and a fifth cylinder operatingmode. In this example, if engine conditions are such that the engine mayoperate in any of the five cylinder modes described, the engine may bedescribed as having five available cylinder operating modes. If two ofthe engine's five operating modes are not available, the engine may bedescribed as having three available operating modes. The engine alwayshas one available cylinder operating mode (e.g., all cylinders activeand combusting air and fuel). Of course, the actual total number ofavailable operating modes may be more than or less than five dependingon the engine configuration.

In still other examples, different cylinder configurations may beprovided. For example, the engine may be a V6 engine or a V10 engine.The different engine configurations may also have different numbers ofcylinder operating modes.

Referring now to FIG. 3A, an example cylinder deactivation region 302for an eight cylinder engine is shown. Cylinder deactivation region 302is shown as being rectangular, but it may be defined by other polygonsor shapes such as a curve that defines a region. Region 302 is definedby a first engine speed 304, a second engine speed 306, a first enginetorque 308, and a second engine torque 310. The second engine speed 306is greater than the first engine speed 304. The second engine torque 310is greater than the first engine torque 308. Cylinder modes where fourand eight cylinders are active may be available within region 302. Eightcylinder mode is the only cylinder mode available outside of region 302.Modes with two active (e.g., cylinders in which air and fuel iscombusted) cylinders are not available in region 302. Cylinder modes maynot be available due to engine noise and vibration. Thus, the actualtotal number of available cylinder modes is greater inside of cylinderdeactivation region 302 than outside of cylinder deactivation region302. Such a cylinder deactivation region may be applied when a vehicleis traveling while the driver is not in a distracted state, when thevehicle is not in an autonomous mode, or when the vehicle is not ashared vehicle. The relatively small size of region 302 and the cylindermodes that are available within region 302 reduces the possibility ofproviding objectionable vehicle operating conditions to vehicleoccupants. The scale of FIG. 3A is the same as for FIG. 3B.

Referring now to FIG. 3B, an example second cylinder deactivation region320 for an eight cylinder engine is shown as a solid line. Cylinderdeactivation region 302 is shown as being trapezoidal, but it may bedefined by other polygons or shapes such as a curve that defines aregion. Region 320 is defined by a first engine speed 322, a secondengine speed 324, a first engine torque 326, and a second engine torque326. The second engine speed 324 is greater than the first engine speed322. The second engine torque 328 is greater than the first enginetorque 326.

Cylinder deactivation region 330 is outlined via a dotted line. Region330 is defined by a first engine speed 322, a second engine speed 323, afirst engine torque 326, and a second engine torque 327. The secondengine speed 323 is greater than the first engine speed 322. The secondengine torque 327 is greater than the first engine torque 326.

Thus, FIG. 3B shows two cylinder deactivation regions. Cylinder modeswhere four and eight cylinders are active may be available within region320. Eight cylinder mode is the only cylinder mode available outside ofregion 320 and outside of region 330. Cylinder modes with two activecylinders, four active cylinders, and eight active cylinders areavailable in region 330. Cylinder modes may not be available due toengine noise and vibration. Thus, the actual total number of availablecylinder modes is greater inside of cylinder deactivation region 330than inside of region 320 or outside of cylinder deactivation regions330 and 320. Such a cylinder deactivation region may be applied when avehicle is traveling while the driver is determined to be in adistracted state, when the vehicle is in an autonomous (self-driving)mode, or when the vehicle is a shared vehicle. The larger regioncomprising region 320 and 330 increases the possibility of improvingvehicle fuel economy. Further, the additional cylinder modes availablein region 330 may also further increase fuel economy. As such, when thevehicle driver is distracted, such as when they are engaged inconversation, engine noise and vibration that may be due to deactivatingengine cylinders may be less noticeable, allowing the engine operatingregion where cylinder deactivation modes that are available to increase.Further, the actual total number of available cylinder modes may beincreased when in-vehicle or ambient noise is elevated, the in-vehicleor ambient noise masking engine noise and vibration from VDE relatedNVH. Finally, when the vehicle is self-driving or when the vehicle isshared, the vehicle operator or vehicle occupant may not be highlyvested in the vehicle, and more willing to tolerate intermittent enginenoise from cylinder deactivation.

In some examples, as depicted, cylinder deactivation region 320 mayinclude a first sub-region 320 a corresponding to the lower speed andtorque part of region 320 and a second sub-region 320 b corresponding tothe higher speed and torque part of region 320. The total number ofcylinder modes available in region 320 may be divided symmetrically orasymmetrically between regions 320 a and 320 b. As an example, twocylinder modes (with relatively higher NVH) may be limited to region 320b while four cylinder modes (with relatively lower NVH) may be limitedto region 320 a. When the vehicle is self-driving and there is a vehicleoccupant, or when the vehicle is shared, or when the driver isdistracted (to a smaller degree), cylinder deactivation may be extendedto region 320 a. When the vehicle is self-driving and there is novehicle occupant or when the driver is distracted (to a higher degree),cylinder deactivation may be further extended to region 320 b.

In some examples, as elaborated at FIG. 7, the controller may selectbetween the regions based on a confidence factor pertaining to driverdistraction, the confidence factor determined based on audio and videofeed captured in the vehicle. For example, driver distraction inferredbased on only audio feed or only video feed may be assigned a lowerconfidence factor. In comparison, if both the audio feed and video feedis indicative of driver distracted behavior, then a higher confidencefactor may be assigned. In response to the lower confidence factor, VDEthresholds may be extended from region 330 to region 320 a. In responseto the higher confidence factor, VDE thresholds may be extended fromregion 330 a to each of region 320 a and 320 b (or from 320 a to 320 b).

In this way, the components of FIGS. 1 and 2A-2B enable a vehicle systemcomprising: an engine having a plurality of selectively deactivatableengine cylinders; a vehicle cabin including speakers, a camera, and amicrophone; a driver actuated button for transitioning the vehiclesystem between an autonomous mode and a driven mode upon actuation ofthe button; and a controller with computer-readable instructions storedon non-transitory memory that when executed cause the controller to:deactivate one or more of the selectively deactivatable engine cylindersresponsive to engine operation in a first engine speed-load range whenthe button is not actuated, the first engine speed-load range adjustedas a function of audio feed and video feed captured at the vehicle; anddeactivate one or more of the selectively deactivatable engine cylindersresponsive to engine operation in a second engine speed-load range whenthe button is actuated, the second engine speed-load range including ahigher engine speed and a higher engine load than the first enginespeed-load range. The controller may also include further instructionsfor adjusting a number of the one or more cylinders deactivated in thefirst engine speed-load range as another function of the audio feed andvideo feed captured at the vehicle, wherein the number of the one ormore cylinders deactivated in the second engine speed-load range ishigher than the number of the one or more cylinders deactivated in thefirst engine speed-load range. For example, the controller may capturethe audio feed via the speakers and the microphone, an upper enginespeed and an upper engine load of the first engine speed-load rangeraised when the captured audio feed includes a higher than thresholdsetting of the speakers or an indication of driver speech; and capturethe video feed via the camera, the upper engine speed and the upperengine load of the first engine speed-load range raised when thecaptured video feed includes gestures indicative of driver distractedbehavior. In one example, the upper engine speed and upper engine loadof the first engine speed-load range is raised by a smaller amount whenone of audio feed and video feed is captured, and wherein the enginespeed-load range is raised by a larger amount when each of audio feedand video feed is captured.

Turning now to FIG. 4, an example method 400 is shown for adjustingenablement of cylinder deactivation based on an indication of driverdistraction. The method enables cylinder deactivation to beopportunistically provided during conditions when NVH associated withthe cylinder deactivation is likely to be masked or otherwise lesslikely to be perceived (and objected to) by a vehicle operator. Byinitiating a VDE transition without dissatisfying a vehicle operator,cylinder deactivation can be provided over a wider range of vehicleoperating conditions, improving fuel economy. Instructions for carryingout method 400 and the rest of the methods included herein may beexecuted by a controller based on instructions stored on a memory of thecontroller and in conjunction with signals received from sensors of theengine system, such as the sensors described above with reference toFIG. 1. The controller may employ engine actuators of the engine systemto adjust engine operation, according to the methods described below.

At 402, the method includes confirming if the vehicle is a sharedvehicle. For example, it may be determined if the vehicle is beingoperated in a shared mode with multiple operators sharing the vehicle.Alternatively, it may be determined if the vehicle is being operated ina cab hailing mode. In certain ride sharing embodiments, a vehicle maybe used by a vehicle operator as a personal vehicle during some periodsand as a shared vehicle or cab during other periods. The vehicleoperator may indicate that the vehicle is being operated as a sharedvehicle via a button on the dashboard, or via an application (e.g.,payment gateway) running on the vehicle's central console.

If the vehicle is in a shared mode, or when the vehicle is beingoperated as a cab, a vehicle operator may be transient owner who may nothave a vested interest in the vehicle engine's smoothness. For example,the car sharing experience may be a “one and done” transaction and theoccupant may not be likely to complain about engine roughness as long asthe vehicle performs the main task of transporting the customer to thedesired location. Accordingly, if the vehicle is a shared vehicle, themethod moves to 406.

If the vehicle is not a shared vehicle, then at 404, it may bedetermined if the vehicle is operating in an autonomous (AV) orself-driving mode. The vehicle may be operated as an autonomous vehiclevia actuation of a button on the dashboard. When the vehicle isdriverless, and without occupants, maximum NVH that can be toleratedallowing the engine controller to control VDE operations with fullliberty. Even if there are occupants in the vehicle, they may betransient occupants who may not have a vested interest in the vehicleengine's smoothness. Accordingly, if the vehicle is a shared vehicle,the method moves to 406.

At 406, the method includes estimating and/or vehicle and engineoperating conditions such as engine speed, vehicle speed, driver torquedemand, MAP, MAT, ambient conditions such as ambient humidity, pressure,and temperature, boost pressure, engine dilution, gear selection, etc.At 408, the method includes transitioning to a VDE mode in anunconstrained manner, or with fewer constraints, based on the engineoperating conditions. In one example, transitioning to the VDE mode withfewer constraints includes increasing the actual total number ofavailable cylinder modes. For example, with reference to FIG. 3B, thecontroller may transition from operating only with cylinder deactivationregion 320 to also including cylinder deactivation region 330. That is,cylinder deactivation may be initiated and completed if engine speed andload conditions are within any of regions 320 and 330. Further, any ofthe cylinder modes available within regions 320 and 330 can be selected,as desired based on the operating conditions. As another example, thecontroller may extend from operating only within cylinder deactivationregion 320 to also operating in cylinder deactivation region 330 a and330 b. In still another example, engine speed and load thresholds atwhich cylinder deactivation is enabled may be extended to include higherengine speeds and loads. The method then ends.

If the vehicle is neither a shared vehicle, nor a vehicle being operatedautonomously, then at 410, the method includes capturing audio and videofeed from within the vehicle cabin as well as from ambient sourcessurrounding the vehicle. Specifically, images and sounds of activitywithin the vehicle, as well as sounds outside the vehicle, may becaptured. The captured images and sounds may include a continuous feed,such as feed captured continuously while the vehicle is travelling withthe engine combusting fuel. Alternatively, images and sounds may becaptured intermittently, at defined intervals. These intervals may bepredefined based on duration of distance of travel (e.g., every second,every minute, every mile of vehicle travels, etc.), and may be furtherbased on vehicle parameters such as vehicle speed, or road grade. Asused herein, captured video feed refers to images (e.g., still images)as well as videos. In addition, audio and video feed may be capturedtogether in a video.

Audio and video feed may be captured by various vehicle sensors anddevices, such as via an on-board camera at 411 a, via on-board speakersat 411 b, via on-board sensors at 411 c, and via machine vision at 411d. Still other devise included microphones, audio sensors, videosensors, communicatively connected devices, etc. For example, aselaborated at FIG. 1, the on-board speaker and microphone may becomponents of a vehicle entertainment system that are repurposed forcapturing vehicle cabin audio input (instead of providing audio outputto the vehicle cabin). Likewise, the on-board camera and machine visionmay be repurposed for capturing vehicle cabin video input (instead ofcapturing video of areas visible from the vehicle cabin).

At 412, the captured audio and video feed is analyzed for conditions andperiods when the driver is distracted, and therefore less likely tonotice engine NVH from cylinder deactivation. As elaborated at FIG. 5,this may include performing voice recognition analysis of the audio feedat 413 a, and performing image analysis of the video feed at 413 b. Forexample, the audio feed may be analyzed to identify the driver's voiceand determine if they are engaged in in-cabin conversation. Likewise,the video feed may be analyzed to identify the driver's behavior.

At 414, it may be determined if driver distracted conditions arepresent. These may be actively distracted or passively distractedconditions. The driver may be determined to be actively distracted when,for example, the analyzed audio or video feed indicates that the driveris engaged in conversation. In other words, the driver may be activelydistracted when the audio or video feed indicates that they are activein communicating. The driver may be determined to be passivelydistracted when, for example, in-cabin noise level is elevated (such asdue to loud music being streamed to the speakers, or due to ambientnoise percolating into the vehicle cabin, etc.).

If the driver is inferred to be distracted, then at 416, the methodincludes adjusting a VDE schedule to opportunistically occur while thedriver is distracted and therefore unlikely to perceive the VDEassociated NVH. Adjusting the VDE schedule may include initiating atransition to the VDE mode as soon as engine speed-load conditions areconducive to cylinder deactivation, and with fewer constraints.Adjusting the VDE schedule may further include increasing the actualtotal number of available cylinder modes. For example, with reference toFIG. 3B, the controller may transition from operating only with cylinderdeactivation region 320 to also including cylinder deactivation region330. That is, cylinder deactivation may be initiated and completed ifengine speed and load conditions are within any of regions 320 and 330.Further, any of the cylinder modes available within regions 320 and 330can be selected, as desired based on the operating conditions. Asanother example, the controller may extend from operating only withincylinder deactivation region 320 to also operating in cylinderdeactivation region 330 a.

As a further example, as elaborated with reference to FIG. 7, thecontroller may extend engine speed and load thresholds for VDE operationbased on a confidence factor pertaining to the driver distraction, asinferred from a comparison of the audio feed and the video feed. Forexample, if only the audio feed is available, only the video feed isavailable, or both feeds are available but only one of them isindicative of distracted driver behavior, then driver distraction isinferred with a lower confidence factor and VDE operations are extendedto a first engine speed-load range beyond the default VDE speed-loadrange. This first range may include engine speeds and loads higher thanand lower than the engine speeds and loads of the default range. If boththe audio and video feeds are available and both are consistent inindicating distracted driver behavior, then driver distraction isinferred with a higher confidence factor and VDE operations are extendedto a second engine speed-load range extending further beyond the defaultrange and the first engine speed-load range. This second range mayinclude engine speeds and load higher than and lower than the enginespeeds and loads of the first range.

In still another example, responsive to a lower confidence factor basedon audio only or video only feed, a first number of cylinderdeactivation modes, larger than the number of default cylinderdeactivation modes, are enabled. In contrast, responsive to a higherconfidence factor, based on each of audio and video feed, a secondnumber of cylinder deactivation modes, larger than the first number ofcylinder deactivation modes, are enabled. As an example, the defaultcylinder deactivation mode for an 8 cylinder engine may include a 4cylinder mode, the first number of cylinder deactivation modes mayextend the options to also include (in addition to the 4 cylinder mode)a 2 and a 3 cylinder mode, while the second number of cylinderdeactivation modes may extend the options to also include (in additionto the 4 cylinder mode) a 5 and a 6 cylinder mode. The method then ends.

If driver distracted conditions are not confirmed, then at 418, themethod includes confirming an upcoming gear shift. The upcoming gearshift may be a gear upshift or downshift that is expected within athreshold duration or distance of travel. An upcoming gear shift may beconfirmed based on navigational input, such as from a GPS, includingroad grade, traffic conditions, vehicle speed (current and expected),etc. The upcoming gear shift may be further based on drive historyincluding how aggressively a driver tends to operate the vehicle, aperformance setting selection (e.g., sport mode, off-road mode, economymode, etc.), as well as current engine speed and load conditions. If agearshift is upcoming, then the VDE transition may be scheduled to occurduring the gearshift so that NVH associated with cylinder deactivationcan be masked by the noise associated with a gearshift. Consequently,the operator may not be dissatisfied as they may be more tolerant of thegearshift noise. The method then ends.

If the driver is not determined to be distracted, and no upcominggearshift can be confirmed either, then at 422, the method includesmaintaining all cylinders active and disabling cylinder deactivationmodes. For example, with reference to FIG. 3B, the controller mayconfine engine operation to a region outside of regions 320 and 330,where all cylinders are maintained active with fuel and valve operationenabled, even if engine speed and load conditions are conducive forcylinder deactivation. In this way, NVH transitions are not allowedduring conditions when a vehicle operator is most likely to perceive andobject to the noise associated with the NVH transition.

It will be appreciated that in addition to enabling a VDE transition tooccur while the driver is distracted, the controller may also enable theVDE transition to occur while the vehicle is travelling on a bumpy road,where the noise and vibration from the bumpy road can mask the NVHassociated with the VDE transition.

Turning now to FIG. 5, an example method is shown for analyzing audioand video feed captured at a vehicle to infer if conditions are presentfor a driver to not be able to perceive or object to VDE related NVH. Inone example, the method of FIG. 5 may be performed as part of the methodof FIG. 4, such as at 412.

At 502, the method includes applying voice recognition and related audioanalyses on captured audio feed. For example, voice recognition softwareor on-board voice recognition techniques may be applied to learn thedriver's voice from among the captured sounds. If the driver is engagedin in-cabin conversation, they may not be likely to notice the NVH. Asanother example, if the audio analysis indicates that the driver isoperating a connected device (e.g., Sync device) which has a microphone,such as when the driver is speaking on the device to give voicecommands, or when the driver is using the connected device to talk withanother person via telephonic communication, the operator is less likelyto notice the NVH as it is not the acoustic focal point of interest.

Based on the analysis, it is determined if the driver is engaged inconversation (either with other vehicle occupants, or to give voicecommands, or via a connected device), then the method moves to 516 toenable a VDE transition if engine speed-load conditions permit cylinderdeactivation. For example, a larger number of cylinder modes are madeavailable and the engine can transition to any of the available modes.For example, an 8-cylinder engine can transition to a 4-cylinder or2-cylinder mode substantially immediately.

If the driver is not engaged in conversation, then at 506, it may bedetermined if the volume of the in-cabin speakers is higher than athreshold. If so, it may be inferred that the in-cabin volume is highenough to mask any VDE associated noise and therefore not beobjectionable to the operator. Therefore, if the volume of the in-cabinspeakers is higher than the threshold, then the method moves to 516 toenable a VDE transition if engine speed-load conditions permit cylinderdeactivation.

If the volume of the in-cabin speakers is below the threshold, themethod to 508 to confirm if ambient noise is higher than a threshold. Inone example, the noise threshold for ambient noise may be different(e.g., higher or lower) than the noise threshold for in-cabin noise (dueto driver conversation or speakers). In another example, the differentnoise thresholds may be a common noise threshold that is elevated enoughto mask engine noise. If the ambient noise is higher than the threshold,it may be inferred that the ambient noise perceived by the operator ishigh enough to mask any VDE associated noise and therefore not beobjectionable to the operator. Accordingly, if the ambient noise ishigher than the threshold, then the method moves to 516 to enable a VDEtransition if engine speed-load conditions permit cylinder deactivation.

Else, if the audio feed is not indicative of conditions where the enginenoise may be masked, then at 514, the method includes maintaining allcylinders active and not enabling cylinder deactivation at this time.For example, none of the cylinder deactivation modes may be permitted toavoid generating noise that is objectionable to the driver.

In parallel to analyzing the audio feed at 502, the controller may alsoanalyze the video feed to determine if the driver is distracted.Specifically, while analyzing the audio feed at 502, the controller mayconcurrently analyze the video feed at 510. Analyzing the video feed mayinclude observing driver behavioral trends including tracking handmovement, eye movement tracking, gestures, etc. Visual context andartificial intelligence may be used to monitor the vehicle driver anddetect whether they are engaging in distracted behavior. As an example,the controller may infer distracted behavior if the driver's eyes arepaying attention to (focusing on) something other than the road. Othergestures indicative of distracted driver behavior include frequent sideto side head movement, eye focus on outside scenery, handmovement/interaction with vehicle cabin controls (HMI), busy steering(vehicle drifting), constant lane changes (in hurry to get todestination), erratic harsh braking, and vehicle speed that consistentlymismatches the advertised road speed.

At 512, it may be determined if the behavior profile of the driver, asbased on the analysis of the video feed, is indicative of a distracteddriver. In one example, the controller may assign the driver a ratinghaving a numerical value corresponding to a degree of distractedbehavior. The higher the rating, the higher the likelihood that thedriver is distracted. If the rating is higher than a defined non-zerothreshold, then it may be determined that the driver is distracted andunlikely to be distracted by any engine noise. Accordingly, if thedriver is indicated to be distracted, then the method moves to 516 toenable a VDE transition if engine speed-load conditions permit cylinderdeactivation. Else, the if the video feed is not indicative ofconditions where the engine noise may be less likely to be perceived bythe driver, then at 514, the method includes maintaining all cylindersactive and not enabling cylinder deactivation at this time. For example,none of the cylinder deactivation modes may be permitted to avoidgenerating noise that is objectionable to the driver.

Turning now to FIG. 7, another example method is shown for analyzingaudio and video feed captured at a vehicle to infer if conditions arepresent for a driver to not be able to perceive or object to VDE relatedNVH. In one example, the method of FIG. 7 may be performed as part ofthe method of FIG. 4, such as at 416. The method of FIG. 7 may also beincluded within the method of FIG. 5. Method 700 enables driverdistraction to be confirmed with a confidence factor based on thecaptured and analyzed audio and video feed, and for VDE operations to becalibrated as a function of the confidence factor.

At 702, the method includes confirming if only (reliable) audio feed hasbeen captured. In one example, only audio feed may be captured if thevehicle does not have a device for capturing video feed, if the devicefor capturing video feed is not functional, or if the quality of thecaptured video feed is not high enough for analysis. If only audio feedis available, at 704, the method includes assigning a confidence factorbased on the analysis of audio feed only and relaxing VDE thresholdsbased on the assigned confidence factor.

At 706, the method includes confirming if only (reliable) video feed hasbeen captured. In one example, only video feed may be captured if thevehicle does not have a device for capturing audio feed, if the devicefor capturing audio feed is not functional, if the cabin speakers arenot functional, or if the quality of the captured audio feed is not highenough for analysis. If only video feed is available, at 708, the methodincludes assigning a confidence factor based on the analysis of videofeed only and relaxing VDE thresholds based on the assigned confidencefactor.

If both audio and video feed is available, then at 710, the methodincludes assigning a confidence factor based on the analysis of audioand video feed and relaxing VDE thresholds based on the assignedconfidence factor. Herein the confidence factor assigned based on boththe audio and video feed is expected to be higher than the confidencefactor assigned based on only the audio feed or only the video feed. Themethod then ends.

As an example, a first confidence factor indicative of driverdistraction may be inferred when only audio feed is available while asecond confidence indicative of driver distraction may be inferred whenonly video feed is available. The first confidence factor may be higheror lower than the second confidence factor based on an analysis of thefeed. For example, the first confidence factor may increase as afrequency of driver speech in the audio feed increases, as based onvoice recognition analysis of the audio feed. As another example, thesecond confidence factor may increase as a frequency of eye movement orhand gestures associated with distracted behavior increases in the videofeed, as based on gesture analysis of the audio feed. In comparison, ifboth the audio feed and video feed is indicative of driver distractedbehavior, then a third confidence factor, higher than each of the firstor the second confidence factor may be assigned. In response to thelower (first or second) confidence factor, VDE thresholds (that isengine speeds and loads at which VDE is allowed to be initiated) may beextended by a smaller amount while responsive to the higher (third)confidence factor, VDE thresholds may be extended by a larger amount,larger than the first amount. For example, if cylinder deactivation isenabled when engine speed and engine load are in a first range,extending VDE thresholds by a smaller amount may include enablingcylinder deactivation when engine speed and engine load are in a secondrange including a higher engine speed and a higher engine load that thefirst range. Likewise, extending VDE thresholds by the larger amount mayinclude enabling cylinder deactivation when engine speed and engine loadare in a third range including a higher engine speed and a higher engineload that the second range.

As another example, if the default VDE threshold includes deactivating afirst number of cylinders when engine speed and load are in a definedrange, extending VDE thresholds by the smaller amount responsive to thelower confidence factor may include enabling a second number ofcylinders, larger than the first number, to be deactivated when enginespeed and engine load are in the given range, and extending VDEthresholds by the larger amount responsive to the higher confidencefactor may include deactivating a third number of cylinders, larger thanthe second number, to be deactivated when engine speed and engine loadare in the given range.

Turning now to FIG. 6, a prophetic example of adjusting VDE transitionsresponsive to driver distraction is shown. Map 600 depicts acceleratorpedal position at plot 602. The accelerator pedal position is indicativeof driver torque demand. Engine speed is shown at plot 604. Typically, atransition between VDE and non-VDE modes is based on engine speed andload changes. In-cabin audio levels, as inferred based on an analysis ofaudio feed captured at the vehicle, if depicted at plot 606. When theaudio levels are higher than threshold 605, it may be inferred that thein-cabin noise is likely to mask engine noise, allowing for cylinderdeactivation to occur without inconveniencing the driver. A driverdistracted state is indicated at plot 608. The driver distracted statemay be based on captured audio feed or video feed. For example, thedriver may be indicated to be distracted when the in-cabin audio levelis elevated or when the in-cabin audio analysis indicates the driver isengaged in conversation. Alternatively, the driver may be indicated tobe distracted based on video analysis of the captured video feed, suchas when the driver is indicated to be intermittently interacting with asynchronized device. A cylinder mode of operation is shown at plot 610.For simplicity, the only modes shown are a VDE mode where half the totalnumber of cylinders are active, and a non-VDE mode where all cylindersare active. However, it will be appreciated that in other examples, anumber of VDE modes may be possible, each with a different total numberof deactivated cylinders (relative to active cylinders). For example, inan 8 cylinder engine, the different modes may include a 4-cylinder mode,a 6 cylinder mode, and a 2 cylinder mode. Vehicle operation via a driverversus via autonomous operation (AV) is depicted at plot 612. When thevehicle is in an AV mode, there is no driver and the vehicle is beingself-driven. The vehicle may or may not have occupants while in the AVmode, such as based on whether the car is being self-driven to pick up acustomer from a location or to transport a customer to a location.

Prior to t1, the operator torque demand is elevated, as indicated byaccelerator pedal depression. At this time, cylinder deactivation is notdesired as all cylinders are required to be active to meet the torquedemand. Accordingly, the engine operates in the non-VDE mode. Also atthis time, the in-cabin audio is lower than threshold 605, and thedriver is not distracted. Shortly before t1, however, the in-cabin audioexceeds the threshold 605, such as due to the driver operating cabinspeakers to listen to music. The driver is inferred to be distracted atthis time. Even though the driver is distracted and unlikely to hear anyengine noise associated with cylinder deactivation, the non-VDE mode ismaintained due to the elevated engine speed and torque demand.

At t1, there is a drop in torque demand that can be met by operatingfewer cylinders. Since the in-cabin noise is above the threshold 605 andthe driver is indicated to be distracted, the engine isopportunistically transitioned to the VDE mode by deactivating enginecylinders. Herein, the transition to the VDE mode occurs while thedriver is less likely to perceive the noise or object to it. This allowsfor the fuel economy associated with VDE operation to be achieved.

Shortly before t2, there is a gradual rise in torque demand. However,the engine speed and load remains low enough for the torque demand to bemet by operating fewer than the full complement of engine cylinders.However, at t2, the in-cabin audio noise falls below threshold 605, suchas due to the driver turning off the cabin speakers. As a result, thedriver is not distracted anymore and is more likely to perceive theengine noise. Therefore, the engine is transitioned back to the non-VDEmode by reactivating previously deactivated cylinders.

At t3, while the torque demand remains conducive to cylinderdeactivation, and the in-cabin audio is below the threshold 605, thedriver is inferred to be in a distracted state based on analysis ofcaptured video feed (not shown). Since the driver is unlikely to noticethe VDE associated NVH at this time, the controller opportunisticallytransitions the engine to the VDE mode by deactivating one or morecylinders. At t4, based on the video feed, it is inferred that thedriver is not distracted anymore. Since the in-cabin audio continues toremain below the threshold 605, the engine is transitioned out of theVDE mode by reactivating the deactivated engine cylinders and operatingwith all cylinders active.

At t5, the vehicle is transitioned to an AV mode. For example, thevehicle driver may exit the vehicle and the vehicle may be commanded todrive itself to an alternate location to pick-up another driver.Therefore at this time there is no vehicle occupant. Accordingly at t5,the engine is transitioned between VDE and non-VDE modes in anunconstrained manner.

In this way, NVH intrusiveness due to VDE operation is reduced. Bymasking noises associated with a VDE event with in-cabin noise, ambientnoise, or driver distraction, the technical effect that is achieved isthat the risk for NVH observation, and objection to it, is lowered. Assuch, this reduces the potential for complaints. By opportunisticallyenabling VDE transitions to occur during conditions when a driver isleast likely to notice the associated NVH, cylinder deactivation can beprovided over a wider range of engine operating conditions, improvingoverall vehicle fuel economy.

One example vehicle method comprises: initiating a transition betweenoperating an engine with more active cylinders to operating with feweractive cylinders in response to one or more of audio and video feedcaptured at the vehicle. In the preceding example, additionally oroptionally, initiating in response to the audio or video feed includesinitiating in response to the one or more of audio and video feed beingindicative of a vehicle driver being actively or passively in adistracted state. In any or all of preceding examples, additionally oroptionally, the method further comprises capturing audio feed of soundinside a vehicle cabin and analyzing the captured audio feed via voicerecognition software to identify a voice of the vehicle driver. In anyor all of preceding examples, additionally or optionally, initiating thetransition in response to the audio feed includes initiating thetransition in response to the captured audio feed indicative of thevehicle driver engaged in in-cabin conversation. In any or all ofpreceding examples, additionally or optionally, the method furthercomprises capturing video feed of driver behavior inside a vehicle cabinand analyzing the captured video feed via image analysis software toidentify a behavioral state of the vehicle driver. In any or all ofpreceding examples, additionally or optionally, initiating thetransition in response to the video feed includes initiating thetransition in response to the captured video feed indicative of thevehicle driver being in the distracted state, the distracted stateincluding driver eyes focusing on something other than a road of vehicletravel. In any or all of preceding examples, additionally or optionally,audio feed includes audio feed from in-cabin speakers, and whereinimitating the transition in response to the audio feed includesinitiating the transition in response to a volume setting of thespeakers being higher than a threshold based on vehicle speed. In any orall of preceding examples, additionally or optionally, audio feedincludes audio feed of ambient noise from an environment of the vehicle,and wherein imitating the transition in response to the audio feedincludes initiating the transition in response to the ambient noisebeing higher than a threshold based on vehicle speed. In any or all ofpreceding examples, additionally or optionally, initiating in responseto one or more of the audio and video feed includes assigning aconfidence factor to the distracted state of the driver based on the oneor more of the audio and video feed; and extending an engine speed-loadthreshold, beyond a default threshold for cylinder deactivation, as afunction of the assigned confidence factor. In any or all of precedingexamples, additionally or optionally, the extending includes initiatingthe transition between operating an engine with more active cylinders tooperating with fewer active cylinders at a higher engine speed and/orhigher engine load than the default threshold as the assigned confidencefactor increases.

Another example method for a vehicle comprises: increasing an actualtotal number of available cylinder modes from a first actual totalnumber of available cylinder modes to a second actual total number ofavailable cylinder modes via a controller in response to audio and videofeed captured inside the vehicle; and operating an engine via thecontroller in a cylinder deactivation mode after increasing the actualtotal number of available cylinder modes. In the preceding example,additionally or optionally, the increasing includes: assigning aconfidence factor associated with a driver distracted state based on theaudio and video feed; and selecting the second actual total number ofavailable cylinder modes based on the assigned confidence factor, thesecond actual total number of available cylinder modes including alarger ratio of deactivated cylinders to active cylinders relative tothe first actual total number of available cylinder modes. In any or allof preceding examples, additionally or optionally, the method furthercomprises extending an engine speed and load threshold at which cylinderdeactivation is initiated beyond a default threshold as the assignedconfidence factor increases. In any or all of preceding examples,additionally or optionally, a lower confidence factor is assigned whenthe driver distracted state is based only on the audio feed or only onthe video feed, and wherein a higher confidence factor is assigned whenthe driver distracted state is based only each of the audio feed and thevideo feed. In any or all of preceding examples, additionally oroptionally, the assigning includes: analyzing the audio feed for avolume setting of in-cabin speakers, operating state of a devicecommunicatively coupled to a vehicle entertainment system, and drivervoice recognition; and analyzing the video feed for driver eye movement,driver hand movement, and defined distracted gestures performed by adriver of the vehicle. In any or all of preceding examples, additionallyor optionally, indicating a driver distracted state responsive to theaudio feed includes one or more of a higher than threshold volumesetting of the in-cabin speakers, actuation of the devicecommunicatively coupled to the vehicle entertainment system, a higherthan threshold frequency of driver speech, and a higher than thresholdvolume of driver speech; and wherein indicating the driver distractedstate responsive to the video feed includes high frequency driver eyemovement, high frequency driver hand movement, and identification of thedefined distracted gestures being actively performed by the driver ofthe vehicle.

Another example vehicle system comprises: an engine having a pluralityof selectively deactivatable engine cylinders; a vehicle cabin includingspeakers, a camera, and a microphone; a driver actuated button fortransitioning the vehicle system between an autonomous mode and a drivenmode upon actuation of the button; and a controller withcomputer-readable instructions stored on non-transitory memory that whenexecuted cause the controller to: deactivate one or more of theselectively deactivatable engine cylinders responsive to engineoperation in a first engine speed-load range when the button is notactuated, the first engine speed-load range adjusted as a function ofaudio feed and video feed captured at the vehicle; and deactivate one ormore of the selectively deactivatable engine cylinders responsive toengine operation in a second engine speed-load range when the button isactuated, the second engine speed-load range including a higher enginespeed and a higher engine load than the first engine speed-load range.In the preceding example, additionally or optionally, the controllerincludes further instructions for adjusting a number of the one or morecylinders deactivated in the first engine speed-load range as anotherfunction of the audio feed and video feed captured at the vehicle,wherein the number of the one or more cylinders deactivated in thesecond engine speed-load range is higher than the number of the one ormore cylinders deactivated in the first engine speed-load range. In anyor all of preceding examples, additionally or optionally, the controllerincludes further instructions for: capturing the audio feed via thespeakers and the microphone, an upper engine speed and an upper engineload of the first engine speed-load range raised when the captured audiofeed includes a higher than threshold setting of the speakers or anindication of driver speech; and capturing the video feed via thecamera, the upper engine speed and the upper engine load of the firstengine speed-load range raised when the captured video feed includesgestures indicative of driver distracted behavior. In any or all ofpreceding examples, additionally or optionally, the upper engine speedand upper engine load of the first engine speed-load range is raised bya smaller amount when one of audio feed and video feed is captured, andwherein the engine speed-load range is raised by a larger amount wheneach of audio feed and video feed is captured.

In a further representation, the vehicle system is a hybrid electricvehicle system.

Note that the example control and estimation routines included hereincan be used with various engine and/or vehicle system configurations.The control methods and routines disclosed herein may be stored asexecutable instructions in non-transitory memory and may be carried outby the control system including the controller in combination with thevarious sensors, actuators, and other engine hardware. The specificroutines described herein may represent one or more of any number ofprocessing strategies such as event-driven, interrupt-driven,multi-tasking, multi-threading, and the like. As such, various actions,operations, and/or functions illustrated may be performed in thesequence illustrated, in parallel, or in some cases omitted. Likewise,the order of processing is not necessarily required to achieve thefeatures and advantages of the example embodiments described herein, butis provided for ease of illustration and description. One or more of theillustrated actions, operations and/or functions may be repeatedlyperformed depending on the particular strategy being used. Further, thedescribed actions, operations and/or functions may graphically representcode to be programmed into non-transitory memory of the computerreadable storage medium in the engine control system, where thedescribed actions are carried out by executing the instructions in asystem including the various engine hardware components in combinationwith the electronic controller.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. For example, the above technology can be applied to V-6,I-4, I-6, V-12, opposed 4, and other engine types. The subject matter ofthe present disclosure includes all novel and non-obvious combinationsand sub-combinations of the various systems and configurations, andother features, functions, and/or properties disclosed herein.

As used herein, the term “approximately” is construed to mean plus orminus five percent of the range unless otherwise specified.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

1. A vehicle method, comprising: initiating a transition betweenoperating an engine with more active cylinders to operating with feweractive cylinders in response to one or more of audio and video feedcaptured at the vehicle.
 2. The method of claim 1, wherein initiating inresponse to the audio or video feed includes initiating in response tothe one or more of audio and video feed being indicative of a vehicledriver being actively or passively in a distracted state.
 3. The methodof claim 2, further comprising, capturing audio feed of sound inside avehicle cabin and analyzing the captured audio feed via voicerecognition software to identify a voice of the vehicle driver.
 4. Themethod of claim 2, wherein initiating the transition in response to theaudio feed includes initiating the transition in response to thecaptured audio feed indicative of the vehicle driver engaged in in-cabinconversation.
 5. The method of claim 1, further comprising, capturingvideo feed of driver behavior inside a vehicle cabin and analyzing thecaptured video feed via image analysis software to identify a behavioralstate of the vehicle driver.
 6. The method of claim 2, whereininitiating the transition in response to the video feed includesinitiating the transition in response to the captured video feedindicative of the vehicle driver being in the distracted state, thedistracted state including driver eyes focusing on something other thana road of vehicle travel.
 7. The method of claim 1, where audio feedincludes audio feed from in-cabin speakers, and wherein imitating thetransition in response to the audio feed includes initiating thetransition in response to a volume setting of the speakers being higherthan a threshold based on vehicle speed.
 8. The method of claim 1, whereaudio feed includes audio feed of ambient noise from an environment ofthe vehicle, and wherein imitating the transition in response to theaudio feed includes initiating the transition in response to the ambientnoise being higher than a threshold based on vehicle speed.
 9. Themethod of claim 2, wherein initiating in response to one or more of theaudio and video feed includes: assigning a confidence factor to thedistracted state of the driver based on the one or more of the audio andvideo feed; and extending an engine speed-load threshold, beyond adefault threshold for cylinder deactivation, as a function of theassigned confidence factor.
 10. The method of claim 9, wherein theextending includes initiating the transition between operating an enginewith more active cylinders to operating with fewer active cylinders at ahigher engine speed and/or higher engine load than the default thresholdas the assigned confidence factor increases.
 11. A method for a vehicle,comprising: increasing an actual total number of available cylindermodes from a first actual total number of available cylinder modes to asecond actual total number of available cylinder modes via a controllerin response to audio and video feed captured inside the vehicle; andoperating an engine via the controller in a cylinder deactivation modeafter increasing the actual total number of available cylinder modes.12. The method of claim 11, wherein the increasing includes: assigning aconfidence factor associated with a driver distracted state based on theaudio and video feed; and selecting the second actual total number ofavailable cylinder modes based on the assigned confidence factor, thesecond actual total number of available cylinder modes including alarger ratio of deactivated cylinders to active cylinders relative tothe first actual total number of available cylinder modes.
 13. Themethod of claim 12, further comprising, extending an engine speed andload threshold at which cylinder deactivation is initiated beyond adefault threshold as the assigned confidence factor increases.
 14. Themethod of claim 12, wherein a lower confidence factor is assigned whenthe driver distracted state is based only on the audio feed or only onthe video feed, and wherein a higher confidence factor is assigned whenthe driver distracted state is based only each of the audio feed and thevideo feed.
 15. The method of claim 12, wherein the assigning includes:analyzing the audio feed for a volume setting of in-cabin speakers,operating state of a device communicatively coupled to a vehicleentertainment system, and driver voice recognition; and analyzing thevideo feed for driver eye movement, driver hand movement, and defineddistracted gestures performed by a driver of the vehicle.
 16. The methodof claim 15, wherein indicating a driver distracted state responsive tothe audio feed includes one or more of a higher than threshold volumesetting of the in-cabin speakers, actuation of the devicecommunicatively coupled to the vehicle entertainment system, a higherthan threshold frequency of driver speech, and a higher than thresholdvolume of driver speech; and wherein indicating the driver distractedstate responsive to the video feed includes high frequency driver eyemovement, high frequency driver hand movement, and identification of thedefined distracted gestures being actively performed by the driver ofthe vehicle.
 17. A vehicle system, comprising: an engine having aplurality of selectively deactivatable engine cylinders; a vehicle cabinincluding speakers, a camera, and a microphone; a driver actuated buttonfor transitioning the vehicle system between an autonomous mode and adriven mode upon actuation of the button; and a controller withcomputer-readable instructions stored on non-transitory memory that whenexecuted cause the controller to: deactivate one or more of theselectively deactivatable engine cylinders responsive to engineoperation in a first engine speed-load range when the button is notactuated, the first engine speed-load range adjusted as a function ofaudio feed and video feed captured at the vehicle; and deactivate one ormore of the selectively deactivatable engine cylinders responsive toengine operation in a second engine speed-load range when the button isactuated, the second engine speed-load range including a higher enginespeed and a higher engine load than the first engine speed-load range.18. The system of claim 17, wherein the controller includes furtherinstructions for adjusting a number of the one or more cylindersdeactivated in the first engine speed-load range as another function ofthe audio feed and video feed captured at the vehicle, wherein thenumber of the one or more cylinders deactivated in the second enginespeed-load range is higher than the number of the one or more cylindersdeactivated in the first engine speed-load range.
 19. The system ofclaim 17, wherein the controller includes further instructions for:capturing the audio feed via the speakers and the microphone, an upperengine speed and an upper engine load of the first engine speed-loadrange raised when the captured audio feed includes a higher thanthreshold setting of the speakers or an indication of driver speech; andcapturing the video feed via the camera, the upper engine speed and theupper engine load of the first engine speed-load range raised when thecaptured video feed includes gestures indicative of driver distractedbehavior.
 20. The system of claim 17, wherein the upper engine speed andupper engine load of the first engine speed-load range is raised by asmaller amount when one of audio feed and video feed is captured, andwherein the engine speed-load range is raised by a larger amount wheneach of audio feed and video feed is captured.